'08 Legacy A/C help?

[racin4ds]

Hi guys, lately I've been having issues with the A/C in my Subaru Legacy. It seems to work great when moving on the road but is terrible at a stop/idle. What causes this? I've verified both the electric fans are working and running full speed. I put a gauge on it and added a half can of R-134 last week and it now sits just above the green area on the cheap gauge that comes with the cans from Autozone.. (don't recall what actual low side pressure was).

If the freon charge is good and the fans are operating, what am I missing? Can't really swing a full service vacuum and recharge ATM...

 

[WobblyElvis]

If the fans are working but they don't seem to help, the only difference is the speed of the compressor. The compressor is being driven faster when driving. Either the compressor is worn or you are still low on refrigerant. It can't cost too much to have a pro just measure the charge.

 

[Chris142]

Throw that stupid can away! You cant get a proper charge without a high side reading. That low side gauge is a gimmick. Go get it properly serviced and tell me what the readings are. Both @idle and revved up.

 

[mclasser]

Try hosing off bugs/debris from the condenser. What's the condition of the serpentine belt?

 

[Nick1994]

As said above, could be worn compressor.

But A/C should be evacuated and recharged by weight with a real A/C machine.

 

[racin4ds]

Originally Posted By: mclasser
Try hosing off bugs/debris from the condenser. What's the condition of the serpentine belt?


Condenser is clean and clear and serp. belt is brand new.

 

[racin4ds]

Originally Posted By: WobblyElvis
If the fans are working but they don't seem to help, the only difference is the speed of the compressor. The compressor is being driven faster when driving. Either the compressor is worn or you are still low on refrigerant. It can't cost too much to have a pro just measure the charge.


The car does have 150k on it, I suppose the compressor could just be worn. Of course it starts acting up in my first summer here in Florida!

A/C places around here all want ~$250 to vacuum down and recharge. It's Florida, I guess AC work is at a premium!

 

[WobblyElvis]

The compressor may have a computer controlled variable stroke. If this is not functioning properly it may perform as you described. You either have to live with it as is or pay for a diagnosis.

Many DIY car owners would have a set of gauges. Maybe you can find a friend of a friend who will check things out for a cheap.

 

[racin4ds]

Originally Posted By: WobblyElvis
The compressor may have a computer controlled variable stroke. If this is not functioning properly it may perform as you described. You either have to live with it as is or pay for a diagnosis.

Many DIY car owners would have a set of gauges. Maybe you can find a friend of a friend who will check things out for a cheap.


I can buy a set, been looking at them recently anyway to check out and learn how to charge my house unit... Rural king has a very nice looking set on sale now for $59.00

 

[CoolShirtDude]

Harbor Freight has a gauge set with hoses and fittings for 49.99 with coupon until 7/31/18

 

[WyrTwister]

That would have been my suggestion . Buy the tooling & service it yourself . Not cheap , but having it serviced is not cheap . At least you will own the tooling .

But do some studying first , before you do any more .

Ann you find the accumulator & the hose from it to the evaporator ? Is it getting cold ?

 

[sxg6]

I think that's just the way it is with Subaru's, or at least our legacies.. The AC in my '09 legacy is pretty weak too. Maybe the problem is just more noticeable now that you're in FL where the outside temp is warmer?

With the fan at max speed, recirc on, my center vent temperature is around 48F. If I lower the fan speed, the temp drops down a little more, but my AC temp has never blown me away. A few years ago I had Subaru evacuate and recharge the system, didn't make any different in the air temperature.

*By the way, be careful if you're going off a generic pressure gauge. The color/psi range might not be accurate for our cars.
Subaru specs are..
With engine @ 1500rpm, set ac to max cool, recirculate on.

Low pressure side 18psi-28psi
High pressure side 213psi-242psi

With outside temp @86F - 95F

 

[Nick1994]

Keep searching and find a good shop.

My grandfather has a 2014 Grand Cherokee, I wanted a buddy of mine who's a mechanic to recharge it properly by weight with his machine. He did and it was slightly low. He said he couldn't charge me much because he didn't really do anything, and it used maybe $2 worth of refrigerant.

LITERALLY popped the hood, connected 2 hoses, typed into the machine how much weight to charge at and walked away. It evacuated and recharged all by itself. It took him 5 minutes tops of labor. I made him take 50 bucks for doing it. He did the same for my Sonata last year.

I doubt you'll be able to find someone to do it that cheap, but it gives you an idea at how little of labor it takes.

 

[sxg6]

^^ It is really cool, I had no idea how they did it until I found this video on youtube a few months ago. I'm not sure if I'm allowed to post youtube links, but it's interesting. I think I've heard that the machines can also inject more oil to make up for any that they take out while evacuating, but I'm not sure about that.

https://youtu.be/IjLfyXCBw1k

 

[racin4ds]

Originally Posted By: sxg6
I think that's just the way it is with Subaru's, or at least our legacies.. The AC in my '09 legacy is pretty weak too. Maybe the problem is just more noticeable now that you're in FL where the outside temp is warmer?

With the fan at max speed, recirc on, my center vent temperature is around 48F. If I lower the fan speed, the temp drops down a little more, but my AC temp has never blown me away. A few years ago I had Subaru evacuate and recharge the system, didn't make any different in the air temperature.

*By the way, be careful if you're going off a generic pressure gauge. The color/psi range might not be accurate for our cars.
Subaru specs are..
With engine @ 1500rpm, set ac to max cool, recirculate on.

Low pressure side 18psi-28psi
High pressure side 213psi-242psi

With outside temp @86F - 95F


Thanks for the specs sxg6! Great info!